ConcurrentHashMap/ConcurrentMap/Map.compute

[Doug Lea]

On 12/06/12 07:29, Doug Lea wrote:

> Actually, it would be a ConcurrentMap spec change, which
> is definitely crossing the line. It will take some
> further thought to see if there is a spec/wording that
> is both safe and useful.
>

Not so hard. All of the
"The default implementation is equivalent to:"
specs and wordings are now completely compatible with
those in ConcurrentMap (which could use a few tiny
touchups someday to clarify this).

This omits the what would have been a nice symmetry
about replace(k, null) and computeIfPresent.  The only
interpretation that works is for replace in
non-null-accepting maps to throw NPE here.
Which is what the j.u.c Maps now do anyway.

I put a viewable version of the javadocs (using JDK7 javadoc) at
http://gee.cs.oswego.edu/dl/wwwtmp/apis/Map.html
(With nested standin versions of Function interfaces
decls for now.) Comments welcome.

I suspect that the style/terminology here of documenting
defaults by saying they are equivalent to code snippets
will usually be the most informative/useful tactic. It
seems to be more understandable than the AbstractCollection
etc style of trying to say it all in words.

-Doug